Human gingival biopsies from pathological-nonpathological sources are used to establish fibroblast cell lines for in vitro analysis and electron microscopic study. The principal objectives are to develop clear interpretations on the biological mechanisms of function and response for human gingival cells and to detect new knowledge about their lysosomal complexes. In particular, the studies are relative to the fibroblast's role in synthesizing, degrading, and remodelling collagen matrices and their response to biological and foreign agents of disease processes.